Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r60db0506b1a90ed00b0e83159f6e7510ab6e4b7b -rd31e9b40e9d56df8fa3551bbba63f6bec3a72811
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 60db0506b1a90ed00b0e83159f6e7510ab6e4b7b)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision d31e9b40e9d56df8fa3551bbba63f6bec3a72811)
@@ -23,6 +23,7 @@
 #include "Level.h"
 #include "MessageSupport.h"
 #include "Messaging.h"
+#include "ModeGenDialysate.h"
 //#include "NVDataMgmt.h"
 #include "OperationModes.h"
 #include "PersistentAlarm.h"
@@ -55,8 +56,8 @@
 #define ADJ_DELTA_TEMP_STEP                                        2.0F                                                            ///< Adjust target temperature based on D28 feedback per cycle.
 #define MAX_ADJ_DELTA_TEMP_C                                       7.0F                                                            ///< Maximum adjusted delta temperature to add/remove from calculated target temperature
 #define D5_HEAT_TX_INIT_FEED_FORWARD                               0.0F                                                            ///< Initial Feed forward term for heater control
-#define D5_HEAT_TX_P_COEFFICIENT                                   0.035F                                                          ///< P Term for AC primary heater control during treatment mode.
-#define D5_HEAT_TX_I_COEFFICIENT                                   0.004F                                                          ///< I Term for AC primary heater control during treatment mode.
+#define D5_HEAT_TX_P_COEFFICIENT                                   0.017F                                                          ///< P Term for AC primary heater control during treatment mode.
+#define D5_HEAT_TX_I_COEFFICIENT                                   0.002F                                                          ///< I Term for AC primary heater control during treatment mode.
 
 #define D45_HEAT_P_COEFFICIENT                                     0.20F                                                           ///< P Term for trimmer heater control.
 #define D45_HEAT_I_COEFFICIENT                                     0.05F                                                           ///< I Term for trimmer heater control.
@@ -427,14 +428,14 @@
 #ifdef __TEENSY_CONDUCTIVITY_DRIVER__
         F32 measuredTempAtDialyzer      = getTeensyConductivityTemperatureValue( D27_COND );
 #else
-        F32 measuredTempAtDialyzer      = getConductivityTemperatureValue( D27_COND );
+        F32 measuredTempAtDialyzer      = getFilteredConductivitySensorTemperature( D27_COND );
 #endif
         F32 calcTargetTemp              = getHeaterTargetTemperature( D5_HEAT );
         F32 dialysateFlowrate           = getTDDialysateFlowrate();
         F32 deltaTempC                  = targetTempfromTD - measuredTempAtDialyzer;
         F32 capDeltaTempC               = MIN( fabs(deltaTempC), ADJ_DELTA_TEMP_STEP );
         F32 ctrl                        = 0.0F;
-
+        F32 updatedTarget               = 0.0F;
 #if 0
         //Assign the initial calcualted temp for adjsutment
         if ( FALSE == isTargetTempAdjusted )
@@ -477,7 +478,9 @@
         }
         else if ( fabs(deltaTempC) >= D5_HEAT_OUT_DEADBAND_CONTROL )
         {
-            ctrl = runPIController( PI_CONTROLLER_ID_D5_HEAT_OUTER_LOOP, targetTempfromTD, measuredTempAtDialyzer );
+            updatedTarget = calculateUpdatedD28TargetDialysateTemp();
+            setHeaterTargetTemperature( D5_HEAT, updatedTarget );
+            ctrl = runPIController( PI_CONTROLLER_ID_D5_HEAT_OUTER_LOOP, getHeaterTargetTemperature( D5_HEAT ), measuredTempAtDialyzer );
             adjustedPrimaryTargetTemp = ctrl;
         }
 
Index: firmware/App/Modes/ModeGenDialysate.c
===================================================================
diff -u -r60db0506b1a90ed00b0e83159f6e7510ab6e4b7b -rd31e9b40e9d56df8fa3551bbba63f6bec3a72811
--- firmware/App/Modes/ModeGenDialysate.c	(.../ModeGenDialysate.c)	(revision 60db0506b1a90ed00b0e83159f6e7510ab6e4b7b)
+++ firmware/App/Modes/ModeGenDialysate.c	(.../ModeGenDialysate.c)	(revision d31e9b40e9d56df8fa3551bbba63f6bec3a72811)
@@ -616,6 +616,35 @@
 
 /*********************************************************************//**
  * @brief
+ * The calculateUpdatedD28TargetDialysateTemp function calculate the delta temperature
+ * required for dialysate temperature to meet the set temperature at dialyzer.
+ * @details \b Inputs: Qd and target temperature.
+ * @details \b Outputs: Adjusted D28 Target temperature
+ * @return none.
+ *************************************************************************/
+F32 calculateUpdatedD28TargetDialysateTemp( void )
+{
+    // Get the dialysate flow rate from TD
+    F32 dialFlowrate            = getTDDialysateFlowrate();
+    F32 deltaTemp               = 0.0F;
+    F32 heatDissipation_b3      = 0.0F;
+    F32 targetTemp              = getTDTargetDialysateTemperature();
+    F32 initialTempAtD28        = 0.0F;
+
+    // Heat loss model predicts the heat loss ( B3) in the DD flow path and
+    // finds the delta temperature to be added with the target temperature
+    // to maintain the target temperature at dialyzer.
+    //Lets calculate B3 heat dissipation factor
+    heatDissipation_b3 = calculateHeatDissipationB3();
+
+    // Reverse calculation of Initial temp at D28 to get the target dialyzer temperature
+    initialTempAtD28 = calculateInitialTemp( targetTemp, heatDissipation_b3 );
+
+    return initialTempAtD28;
+}
+
+/*********************************************************************//**
+ * @brief
  * The monitorChamberLevelStatus function checks the spent chamber and bicarb
  * chamber level status and updates the corrosponding flags.
  * @details \b Inputs: Spent and bicarb chamber levels.
Index: firmware/App/Modes/ModeGenDialysate.h
===================================================================
diff -u -rb2e7c9194acd84783d2bbad64c5720410493e199 -rd31e9b40e9d56df8fa3551bbba63f6bec3a72811
--- firmware/App/Modes/ModeGenDialysate.h	(.../ModeGenDialysate.h)	(revision b2e7c9194acd84783d2bbad64c5720410493e199)
+++ firmware/App/Modes/ModeGenDialysate.h	(.../ModeGenDialysate.h)	(revision d31e9b40e9d56df8fa3551bbba63f6bec3a72811)
@@ -52,6 +52,7 @@
 U32  transitionToGenDialysateMode( void );                  // Prepares for transition to gen dialysate mode
 U32  execGenDialysateMode( void );                          // Execute the gen dialysate mode state machine (call from OperationModes)
 void execGenDialysateMonitor( void );                       // Dialysate generation monitor
+F32 calculateUpdatedD28TargetDialysateTemp( void );         // Calculated updated D28 temperature with Ultrafilters heat loss
 
 BOOL hydChamberWaterInletControl( void );                   // Hydraulics chamber inlet water control
 DD_GEND_MODE_STATE_T getCurrentGenDialysateState( void );   // Get the current state of the gen dialysate mode.